Analysis Hook-Release Gear Mechanism Before the recovery of the starboard lifeboat, the crew had difficulties lowering the release handle to its final position. Additional force by two crew members was applied in order to lower the release handle to a position where the safety pin could be inserted. In this instance, the release handle and the cable attachment bracket were found deformed and the safety pin inserted, but not rotated into its locked position (see Photos 4 and 5). Photo4.Deformation of release handle, with safety pin not rotatedinto locked position Photo5.Deformation of releasecable attachment bracketaligned When the release handle is lowered with the lock piece in an intermediate position, the lock piece interferes with the cam rotation. Any additional force applied on the release handle will translate into the release cable attachment bracket being deformed. The greater the deformation, the closer the release handle will be to its reset (final) position. With each subsequent deformation, and closer to final positioning of the reset handle, it becomes more likely that, given the short distance needed to achieve the goal of inserting the safety pin, an operator will attempt to force the system. During the post-occurrence salvage, as the starboard lifeboat was being raised from the water, the cam lever on the aft hook assembly was observed as not being in the horizontal reset position (see Photos 6 and 7); hence, the hooks were not locked in place before the recovery. Photo6.Deformation of release handle, with safety pin not rotated into lockedposition Photo7.Deformation of releasecable attachment bracketaligned Although the release handle was locked by the safety pin, the cams (both fore and aft) were not fully rotated under their respective lock pieces. The interference resulting from the incorrect re-setting of the hooks, combined with the force required to insert the safety pin, accounted for the subsequent residual compression force in the release cables/cam lever assembly.4 This in turn generated sufficient friction between the cam edge and the lock piece to hold the hook in place and bear the load of the lifeboat. While the lifeboat was being hoisted, it was in a quasi-static state- at least until the floating blocks reached the davit arms, at which point the shock resulting from impact overcame the friction that held the aft hook in place. This released the davit fall long link. As the lifeboat's aft end began to fall, the load was transferred to the improperly reset forward hook, which could not absorb the additional load and released, allowing the lifeboat to fall. Even though the mechanism is set improperly, an operator can be deceived that the mechanism is operating safely by lowering the release handle into position and being able to insert the safety pin. This false sense of security is enhanced by the hooks remaining in vertical position, capable of holding the lifeboat during the hoisting operation. At the International Maritime Organization (IMO) Maritime Safety Committee (MSC) 82ndsession held in November2006, a proposal was drafted regarding the prevention of the accidental release of lifeboats during recovery.5 ...3 to prevent an accidental release during recovery of the boat, unless the hook is completely reset, either the hook shall not be able to support any load, or the handle or safety pins shall not be able to be returned to the reset (closed) position without excessive force. Additional danger signs shall be posted at each hook station to alert crew members to the proper method of resetting; The large number of often complex designs, combined with the fact that crew members rarely return to the same vessel, creates a lack of familiarity with an essential piece of lifesaving equipment, thereby continuing to put seafarers at risk. History of Improper Resetting The interference or lack of clearance can be seen in Photos 8 and 9. These photos show multiple indentations where the cam previously interfered with the lock piece of the starboard lifeboat. Photo8.Indentations on aft hook lock piece caused by contact withtop edge of cam Photo9.Indentations on forward hook lock piece caused by contactwith top edge of cam The multiple indentations on the lock piece, caused by contact with the cam edge, suggest that this scenario had taken place before- a repeated pattern of improper resetting that put the safety of crew and equipment at risk. Crew Training and Familiarization Training Material Before this occurrence, training consisted of a brief, on-site system familiarization and a request that crew members read the instruction manuals. Reportedly, they did read the manuals and acknowledged having understood the mechanism. However, physical evidence as found on the mechanism pieces suggests that this was not the case and hence the onboard training did not meet its objectives. There was no formal knowledge evaluation after the drills, nor was there any hands-on training. The next opportunity for the crew to interact with the mechanism was not until the day of the occurrence. The successful resetting of the hooks is paramount to properly resetting the release gear mechanism, with the essential point being an understanding of the interaction between the hook and the lock piece. Although the SRS-37 instruction manual addresses the issue of clearance and interference between the lock piece and the rotating cam, the manual does not draw the user's attention to why the lock piece can pivot back down, nor does the manual highlight the need to maintain constant pressure on the hook until the cam is fully rotated. The IMO has previously recognized that user-friendly manuals for lifeboat systems- especially for release gear systems- are important to help preventing casualties.6 The Marine Accident Investigation Branch (MAIB) of the United Kingdom also recognizes the need to explain the reasoning behind a given procedure: For training material to be effective ...knowing why things are done... will do much to ensure [a] trainee understands the procedures and will remember them when under pressure. Inspection of many training manuals reveals they do not extend this far.7 Content could, for example, include "an explanation of the structure and working principle of the major parts,"8 the relationship between diagrams and text, and a comprehensive step-by-step approach- all of which contribute to a better understanding. Without full comprehension of the reasons for a given procedure, there exists a risk that crews may not place adequate emphasis on instruction manuals, particularly when very different release mechanisms can look very similar. Hands-on Training Subsequent to joining the vessel, crew members were told to read the manual for the lifeboat, which includes the hook-release gear mechanism. There was no confirmation or evaluation that the material had been understood and that crew members were proficient with its use. Release gear mechanisms come in a variety of designs. It is therefore crucial that crews be proficient with the use of the onboard equipment. To be effective, the knowledge gained from any training manual must be applied to an actual hands-on situation- preferably a stress-free environment before actually conducting a drill- which allows for safe trial and error. This process transforms theoretical knowledge into practical understanding and skill. It is also recognized that training enhanced with models or replicas improves knowledge transfer. Failure to confirm that theoretical knowledge has been safely transformed into practical understanding and skill will continue to put users of release gear mechanisms at risk. The aft release mechanism opened with the impact of the floating blocks on the davit arms. The load was then transferred to the forward hook, which, due to improper resetting, released and caused the lifeboat to fall. Because the hooks were not held in their proper position during the reset of the release mechanism, the hooks were improperly reset. Residual compressive force in the release cable allowed the lock piece to be held in place by friction alone, making hoisting of the lifeboat possible. The deformation of the release cable attachment enabled the release handle to be secured in the reset position even though the hook-release mechanism was not properly reset. The combination of reading the instruction manual and a pre-drill training session was insufficient to ensure that crew members fully understood how to reset the hook-release mechanism.Findings as to Causes and Contributing Factors The aft release mechanism opened with the impact of the floating blocks on the davit arms. The load was then transferred to the forward hook, which, due to improper resetting, released and caused the lifeboat to fall. Because the hooks were not held in their proper position during the reset of the release mechanism, the hooks were improperly reset. Residual compressive force in the release cable allowed the lock piece to be held in place by friction alone, making hoisting of the lifeboat possible. The deformation of the release cable attachment enabled the release handle to be secured in the reset position even though the hook-release mechanism was not properly reset. The combination of reading the instruction manual and a pre-drill training session was insufficient to ensure that crew members fully understood how to reset the hook-release mechanism. Although the instruction manual conformed to the International Maritime Organization format, its contents were less than adequate for a complete and thorough understanding. Some release gear mechanisms can appear to be properly secured even though they are not- creating a false sense of security that continues to place the lives of crew members at risk. Failure to ensure that theoretical knowledge concerning lifesaving equipment including release gear mechanisms has been safely transformed into practical understanding will continue to put seafarers at risk.Findings as to Risk Although the instruction manual conformed to the International Maritime Organization format, its contents were less than adequate for a complete and thorough understanding. Some release gear mechanisms can appear to be properly secured even though they are not- creating a false sense of security that continues to place the lives of crew members at risk. Failure to ensure that theoretical knowledge concerning lifesaving equipment including release gear mechanisms has been safely transformed into practical understanding will continue to put seafarers at risk. Safety Action Taken Transportation Safety Board On 27 October 2006, the TSB made a presentation to the manufacturer, the classification society, and representatives from the vessel's Protection and Indemnity Club (P I) regarding the identified safety deficiencies. As part of the presentation, animations were created of both a proper and improper resetting of the release mechanism. On 30November2006, the TSB issued Marine Safety Advisory (MSA) 11/06 to Transport Canada (TC), to request that the Paris and Tokyo Memorandum of Understanding (MOU) secretariats be informed that all vessels equipped with the type SRS-37 release gear mechanisms should be inspected, and that the ability of each ship's crew to safely operate the release mechanism be verified accordingly. This MSA was issued because it was felt that the manufacturer might not be in a position to ensure that all affected vessels were made aware of the design and operation inadequacies of this release gear mechanism. International Maritime Organization The International Maritime Organization (IMO) issued the following documentation related to lifeboat release mechanisms: MSC.1/Circ.1205; MSC.1/Circ. 1206; and Resolution MSC.218 (82) (see AppendixC), adopted 08December2006, Adoption of Amendments to the International Life-Saving Appliance (LSA) Code Transport Canada In response to the aforementioned MSA, TC advised the Paris and Tokyo MOU secretariats of this Port State Control issue and provided them with a copy of the TSB's MSA. The secretariats have sent a circular to their members with respect to the advisory notice, and the Paris MOU secretariats have posted the explanatory animation files on their Web sites for their members. Furthermore, TChas made its inspectors aware of the content of IMO Resolution MSC.218(82), relating to the general requirements for lifeboats.9 Manufacturer Shortly after the occurrence, the manufacturer took measures to review its instruction manual. After a review of the updated manual, the TSB determined that a risk remains that users might secure the release handle in the closed position without the hook being properly reset. Consequently, Marine Safety Information letter 08/06, concerning the updated instruction manual, was issued on 07 December 2006 to the manufacturer. The manufacturer replied that it considered the updated manual to be adequate. Later, in March 2007, the manufacturer published a safety guidance specifically for the type SRS-37 release gear mechanism.10 Ship Management The ship management company distributed to all ships under its control a safety instruction circular related to lifeboat operations. The ship management company forwarded a copy of the internal investigation report to the ship's flag state indicating corrective and preventive measures. Classification Society Nippon Kaiji Kyokai In October 2006, Nippon Kaiji Kyokai (Class NK) issued Technical Information Bulletin TEC-067611 requiring that an overhaul of the unload release gear be carried out in the presence of a surveyor, and that this be done by a manufacturer's representative or person appropriately trained and certified by the manufacturer in accordance with MSC.1/Circ.1206.12 On 13 April 2007, following the publication of the safety guidance by the manufacturer, ClassNK issued Technical Information Bulletin TEC-0694 regarding the type SRS-37 release gear mechanism on the manufacturer's lifeboats.